What Is This?

[Rmerriett]

At first this was brown hairy looking stuff which i assumed was algea. Today i came home to this. It looks like worms growing out of the leaves. What is it, and what causes it?

 

[skija]

Staghorn , low co2 or big organic waste in tank

 

[Rmerriett]

Thank you

 

[skija]

Trim the affected plants , they will not recover , the new growth should be fine if you find the problem